Farnesene-based macromonomers and methods of making and using the same

ABSTRACT

A macromonomer precursor is provided that includes a polymeric chain derived from farnesene and a single functional terminal end. The functional terminal end may include a hydroxyl group, an amino group, an epoxy group, an isocyanato group, or a carboxylic acid group. The terminal end of the macromonomer precursor may then be reacted with a (meth)acrylate to form a macromonomer having a (meth)acrylate functionalized terminal end that may be (co)polymerized with radically polymerizable monomers, such as alkyl(meth)acrylate monomers. Alternatively, a copolymer may be obtained by first deriving a poly(meth)acrylate from (meth)acrylate monomers having reactive groups that would allow the macromonomer precursors to be grafted onto the poly(meth)acrylate in a second step. The resulting copolymer may be incorporated as an additive in various formulations, such as a lubricant, a hydraulic fluid, a cosmetic composition, and an adhesive composition.

TECHNICAL FIELD

The present subject matter relates to macromonomers derived frompolyfarnesene precursors that may be functionalized and thenco-polymerized with radically polymerizable monomers, such asalkyl(meth)acrylates. Alternatively, the macromonomer precursors may begrafted onto a (co)polymer derived from radically polymerizablemonomers. The resulting (co)polymers may be used in variousformulations, such as lubricants, hydraulic fluids, cosmetics, andadhesives.

BACKGROUND

Macromonomers may be used to form comb or star shaped copolymers thatare incorporated into compositions to enhance the properties of thecomposition. For example, the copolymer may include a polymeric backbonewith a portion of the macromonomers forming side chains off of thebackbone. The polymeric backbone may be derived from polar monomers,such as (meth)acrylates, while the macromonomers may be derived fromnon-polar monomers, such as butadiene or isoprene, that are polymerizedand terminally functionalized. Examples of applications for suchcopolymers include viscosity index improvers for lubricant and hydraulicfluid compositions, water resistance additives for cosmeticcompositions, and adhesion promoters in pressure sensitive adhesivecompositions.

The macromonomers may be made by first manufacturing a precursor byanionic polymerization of a monomer, such as butadiene. Anionicpolymerization allows for the control of the molecular weight, molecularweight distribution, and controlled reaction of the living chain ends.By controlling the macrostructure, rheological properties of themacromonomers can also be controlled. For example, it is known by thoseof skill in the art that molecular weight of the polymer is proportionalto viscosity. Therefore, when a high molecular weight macromonomer isdesired, the result may be a macromonomer of high viscosity that isdifficult to process.

In many applications, consumers prefer that the macromonomer be providedin the form of a hydrogenated amorphous liquid. This may be accomplishedby controlling the microstructure of the macromonomer and viahydrogenation. For example with respect to polybutadiene-basedmacromonomers, polar modifiers added to the solution for anionicpolymerization, such as Lewis bases, are most often employed to controlthe level of vinyl structures in the resulting macromonomer. It has beenreported that a minimum vinyl enchainment of 40% by weight is necessaryto maintain a liquid, non-crystalline form for polybutadiene afterhydrogenation.

Thus, there is a need for improved macromonomers and methods forobtaining macromonomers provided in the form of amorphous liquids thathave relatively low viscosity for easier processing.

SUMMARY

According to one embodiment, a macromonomer precursor is provided thatcomprises a polymeric chain derived from farnesene and a singlefunctional terminal end selected from a hydroxyl group, an amino group,an epoxy group, an isocyanato group, or a carboxylic acid group.

According to another embodiment, a copolymer is provided, wherein thecopolymer is derived from monomers comprising radically polymerizablemonomers and one or more macromonomers comprising a polymeric chainderived from farnesene and a (meth)acrylate functionalized terminal end.Various methods of obtaining the copolymer are also provided.

According to yet another embodiment, a copolymer is provided, whereinthe copolymer is derived from first radically polymerizing(meth)acrylate monomers that include a reactive group to form a poly(meth)acrylate, and then reacting a macromonomer precursor in a secondstep with the reactive groups to graft the macromonomer precursor to thepoly(meth)acrylate.

The copolymers may be incorporated in various formulations, such aslubricants, hydraulic fluids, cosmetics, or adhesives.

Additional objects, advantages and novel features of the examples willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing and the accompanying drawings or may be learned by productionor operation of the examples. The objects and advantages of the presentsubject matter may be realized and attained by means of themethodologies, instrumentalities and combinations particularly pointedout in the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plot of molecular weight vs. viscosity for samples of amacromonomer precursor as described herein compared to a polybutadienemacromonomer precursor.

FIG. 2 is a plot of temperature vs. viscosity for samples of amacromonomer precursor as described herein compared to a polybutadienemacromonomer precursor.

FIG. 3 is a plot of Tg vs. 1,2/3,4 content for samples of polyfarnesene,polybutadiene, and polyisoprene.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, compounds,and/or compositions have been described at a relatively high-level,without detail, in order to avoid unnecessarily obscuring aspects of thepresent teachings.

As used herein, throughout the specification and the claims,“macromonomer” means a macromolecule that has one end-group whichenables it to act as a monomer molecule, contributing only a singlemonomeric unit to a chain of a polymer or oligomer. Furthermore, as usedherein, throughout the specification and the claims, “(co)polymer” meanshomopolymer or co-polymer, and “(meth)acrylate” means acrylate ormethacrylate.

It has now been found that farnesene-based macromonomer precursors maybe at least partially hydrogenated to form an amorphous liquid thatexhibits very low viscosity as a function of molecular weight comparedwith diene-based macromonomer precursors, including those prepared frombutadiene or isoprene. The macromonomer derived from these precursorsalso exhibit improved rheological properties. The practical result isthat the macromonomer precursors and the macromonomers made therefromremain liquid in form at molecular weights well above the molecularweight in which diene-based macromonomers, such as butadiene, becomesolid materials. In addition, the farnesene-based macromonomers exhibitlow glass transition temperature (Tg) with decreased dependence on theirmicrostructure. In contrast, butadiene-based macromonomers exhibit arange of Tgs depending on the amount of vinyl enchained in the backbone,as previously noted. Butadiene-based macromonomer precursors of lowvinyl content that exhibit the same Tgs as the farnesene-basedmacromonomer precursors disclosed herein become semi-crystalline duringhydrogenation, resulting in insoluble materials. Surprisingly, the lowTg, low 1,2 and 3,4 polymerization farnesene-based macromonomerprecursors disclosed herein become an amorphous liquid even afterhydrogenation.

According to the examples disclosed herein, farnesene-basedmacromonomers are provided that may be provided in the form of anamorphous liquid and exhibit much lower viscosity when compared tomacromonomers based on dienes of equivalent molecular weight. Thefarnesene-based macromonomers may be derived from precursors in the formof an amorphous liquid exhibiting substantially lower viscosity than adiene-based precursor of equivalent molecular weight. The precursors mayalso be used similarly to the macromonomers by forming side chainsgrafted on the polymeric backbone of a (co)polymer. Thus, themacromonomer precursors disclosed herein may comprise a polymeric chainderived from farnesene; and a single functional terminal end selectedfrom a hydroxyl group, an amino group, a carboxylic acid group, anisocyanato group, and an epoxy group.

Because of the lower inherent viscosity of the macromonomers disclosedherein, macromonomer formulations may be easily processed (e.g. mixed,coated, sprayed, etc.) without significant dilution with othercomponents. The farnesene-based macromonomer may be used as theexclusive macromonomer or blended into compositions containing othermacromonomers, such as diene-based macromonomers. The functionalend-groups for the macromonomer may include a (meth)acrylate, which maybe obtained from the macromonomer precursors having a hydroxyl endgroup, amino end group, epoxy end group, isocyanato group, or carboxylicacid end group, as described in greater detail below. The macromonomerprecursors may be obtained by anionic polymerization of farnesenemonomers alone or in combination with other monomers, such as dienes andvinyl aromatics.

Farnesene exists in isomer forms, such as α-farnesene((E,E)-3,7,11-trimethyl-1,3,6,10-dodecatetraene) and β-farnesene(7,11-dimethyl-3-methylene-1,6,10-dodecatriene). As used in thespecification and in the claims, “farnesene” means (E)-β-farnesenehaving the following structure:

as well as (E)-β-farnesene in which one or more hydrogen atoms have beenreplaced by another atom or group of atoms (i.e. substituted).

The farnesene monomer used to produce various embodiments of themacromonomer precursor according to the disclosed methods andcompositions may be prepared by chemical synthesis from petroleumresources, extracted from insects, such as Aphididae, or plants.Therefore, an advantage of the disclosed methods and compositions isthat the precursor may be derived from a monomer obtained via arenewable resource. The monomer may be prepared by culturing amicroorganism using a carbon source derived from a saccharide. Thefarnesene-based macromonomer precursor according to the disclosedmethods and compositions may be efficiently prepared from the farnesenemonomer obtained via these sources.

The saccharide used may be any of monosaccharides, disaccharides, andpolysaccharides, or may be a combination thereof. Examples ofmonosaccharides include, without limitation, glucose, galactose,mannose, fructose, and ribose. Examples of disaccharides include,without limitation, sucrose, lactose, maltose, trehalose, andcellobiose. Examples of polysaccharides include, without limitation,starch, glycogen, and cellulose.

The cultured microorganism that consumes the carbon source may be anymicroorganism capable of producing farnesene through culturing. Examplesthereof include eukaryotes, bacteria, and archaebacteria. Examples ofeukaryotes include yeast and plants. The microorganism may be atransformant obtained by introducing a foreign gene into a hostmicroorganism. The foreign gene is not particularly limited, and may bea foreign gene involved in the production of farnesene because it canimprove the efficiency of producing farnesene.

In the case of recovering farnesene from the cultured microorganism, themicroorganism may be collected by centrifugation and disrupted, and thenfarnesene can be extracted from the disrupted solution with a solvent.Such solvent extraction may appropriately be combined with any knownpurification process such as distillation.

Any methods known by those having skill in the art may be used toprovide the farnesene-based macromonomer precursors described herein.Anionic polymerization may be desirable because anionic polymerizationallows greater control over the final molecular weight of the precursor,i.e. narrow molecular weight distributions and predictable molecularweights. The living terminal end of the precursor may also be easilyquenched, for example, by using an alkylene oxide followed by contactwith a protic source providing a monol. As previously noted, the lowviscosity farnesene-based macromonomers may be derived by polymerizingfarnesene monomer alone or with at least one other monomer, such asbutadiene or isoprene. For example, the macromonomer precursors madeaccording to various embodiments of the disclosed methods andcompositions are composed of at least 25 wt. % farnesene.

The farnesene-based macromonomer precursors described herein may beprepared by a continuous solution polymerization process wherein aninitiator, monomers, and a suitable solvent are continuously added to areactor vessel to form the desired precursor. Alternatively, thefarnesene-based macromonomer precursors may be prepared by a batchprocess in which all of the initiator, monomers, and solvent arecombined in the reactor together substantially simultaneously.Alternatively, the farnesene-based macromonomer precursors may beprepared by a semi-batch process in which all of the initiator andsolvent are combined in the reactor together before a monomer feed iscontinuously metered into the reactor.

Initiators for providing a macromonomer precursor with a living terminalchain end include, but are not limited to, organic salts of alkalimetals. The polymerization reaction temperature of the mixture in thereactor vessel may be maintained at a temperature of about −80 to 80° C.

As understood by those having skill in the art, living anionicpolymerization may continue, as long as monomer is fed to the reaction.The farnesene-based macromonomer precursors may be obtained bypolymerization of farnesene and one or more comonomers. Examples ofcomonomers include, but are not limited to, dienes, such as butadiene,isoprene, and myrcene, or vinyl aromatics, such as styrene and alphamethyl styrene. In one embodiment of the disclosed methods andcompositions, a method of manufacturing a farnesene-based macromonomerprecursor may comprise polymerizing a monomer feed, wherein the monomerfeed comprises farnesene monomer and optionally at least one comonomerin which the comonomer content of the monomer feed is ≦75 wt. %,alternatively ≦50 wt. %, or alternatively ≦25 wt. %, based on the totalweight of the monomer feed. The polymerization conditions and monomerfeed may be controlled as may be desired so as to provide, for example,macromonomer precursors having a random, block or gradient structure.

The farnesene-based macromonomer precursors according to embodiments ofthe disclosed methods and compositions may have a number averagemolecular weight greater than or equal to 1,000 g/mol and less than orequal to 100,000 g/mol, alternatively less than or equal to 50,000g/mol, as measured through a gel permeation chromatograph and convertedusing polystyrene calibration. The farnesene-based macromonomerprecursors may have a viscosity less than or equal to 300,000 cP,alternatively less than 200,000 cP, or alternatively less than or equalto 30,000 cP, at 25° C.

Upon reaching a desired molecular weight, the macromonomer precursor maybe obtained by quenching the living terminal end with a compound havingthe selected functionality or by providing the terminal end with areactive group that may be subsequently functionalized. The macromonomerprecursor, as noted previously, may be provided in the form of apolyfarnesene having either a hydroxyl, carboxylic acid, amino,isocyanato, or epoxy end group.

For the macromonomer precursor provided in the form of a polyfarnesenehaving a hydroxyl end group, anionic polymerization may be concluded bya quenching step in which the living terminal end of the polyfarneseneis reacted with an alkylene oxide, such as propylene oxide, and a proticsource, such as an acid, resulting in a monol, i.e. a hydroxyl group onone of the terminal ends of the precursor.

In another example, the macromonomer precursor may be provided in theform of a polyfarnesene having a carboxylic acid end group. In onemethod, following anionic polymerization of farnesene monomers toprovide a polyfarnesene chain having a living terminal end, the livingterminal end may be contacted with carbon dioxide gas to provide theterminal end with a carboxylate followed by quenching the carboxylatewith an acid, such as hydrochloric, phosphoric, or sulfuric acid toconvert the carboxylate into a carboxylic acid. In another method, thecarboxylic acid-terminated polyfarnesene may be obtained by reacting apolyfarnesene-based monol with a cyclic anhydride. Examples of cyclicanhydrides include, but are not limited to, phthalic anhydride, succinicanhydride, maleic anhydride, trimellitic anhydride, hexahydrophthalicanhydride, methyltetrahydrophthalic anhydride, itaconic anhydride,pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, andcyclopentanetetracarboxylic dianhydride.

In yet another example, the macromonomer precursor may be provided inthe form of a polyfarnesene having an amino end group. In one method, apolyfarnesene based monol may be reacted with an alkane- orarenesulfonyl chloride or fluoride in the presence of a tertiary aminecatalyst to form an alkane- or arenesulfonate terminated precursor. Thealkane- or arenesulfonate terminated polymer may then be reacted with aprimary amine or ammonia to provide the amine-terminated polyfarnesenemacromonomer precursor.

Typical alkane- or arenesulfonyl compounds include, but are not limitedto, methanesulfonyl chloride, methanesulfonyl fluoride, ethanesulfonylchloride, ethanesulfonyl fluoride, p-toluenesulfonyl chloride, andp-toluenesulfonyl fluoride. Primary amines that may be reacted with thealkane- or arenesulfonate terminated polymer include, for example,ethylamine, propylamines, allylamine, n-amylamine, butylamines,cyclohexylamine, n-tetradecylamine, benzylamine, aniline, toluidines,naphthylamine and the like.

In an alternative method for producing an amine-terminated precursor, apolyfarnesene-based monol may be directly reacted with ammonia. Forexample, as explained above, the polyfarnesene-based monol may beprovided by anionic polymerization of farnesene monomers in which theliving terminal ends of the polymer are quenched using an epoxidefollowed by contact with a protic source. If the epoxide used is analkylene oxide having the following structure:

in which R is a C1-C20 alkyl group, the resulting monol will be asecondary alcohol. The secondary hydroxyl-groups may then be reacteddirectly with ammonia in the presence of hydrogen and a catalyst underpressure (e.g. >2 MPa) to provide amine-terminated macromonomerprecursors. A stoichiometric excess of ammonia with respect to thehydroxyl groups may be used. Examples of catalysts for the aminationinclude, but are not limited to, copper, cobalt and/or nickel, and metaloxides. Suitable metal oxides include, but are not limited to, Cr₂O₃,Fe₂O₃ ZrO₂, Al₂O₃, and ZnO.

In yet another method, the macromonomer precursor having an amino endgroup may be obtained by adding acrylonitrile to either a primary orsecondary OH end of a monol through Michael addition, followed byreduction to form a primary amino group at a terminal end. Thepolyfarnesene-based monol may be dissolved in an organic solvent andmixed with a base to catalyze the reaction. Examples of bases include,but are not limited to, alkali metal hydroxides and alkoxides, such assodium hydroxide. Acyrlonitrile may then be added to the catalyst/monolmixture dropwise. The Michael addition of acrylonitrile(cyanoethylation) to the monol will form the correspondingcyanoalkylated compound.

In yet another example, the farnesene-based macromonomer precursor maybe provided with an epoxy end group by, for example, a two-step process.In a first step, a polyfarnesene monol and a monoepoxy compound may becombined in a solvent and allowed to react under pressure or in thepresence of an inert gas, such as nitrogen or a noble gas. Examples ofmonoepoxy compounds include epihalohydrins, such as epichlorohydrin,beta-methylepichlorohydrin and epibromohydrin. The reactants may beoptionally mixed with a catalyst, such as a metal salt or semimetalsalt, the metal being selected from boron, aluminium, zinc and tin, andat least one anion selected from F⁻, Cl⁻, BF₄ ⁻, PF₆ ⁻, AsF₆ ⁻, SbF₆ ⁻,ClO₄ ⁻, IO₄ ⁻, and NO₃ ⁻. Following the first step, excess monoepoxycompound may be removed by distillation, for example, and then at leastone alkali metal hydroxide may be added to the reaction mixture in orderto form an alkali metal halide and the glycidyl-terminated precursor.

According to yet another example, the farnesene-based macromonomerprecursor may be provided with an isocyanato end group. This may beaccomplished by, for example, reacting a farnesene-based macromonomerprecursor having an amino end group with phosgene.

As understood by one of skill in the art, the reactants used to providethe macromonomer precursors may be dissolved in a suitable organicsolvent and heat and/or pressure may be applied to the reaction topromote formation of the macromonomer precursors. The reaction may becarried out batchwise or as a semicontinuous or continuous process. Thereaction products may be recovered and treated by any conventionalmethod, such as distillation, evaporation or fractionation to effectseparation from unreacted material, solvent, if any, and by products.

The farnesene based macromonomer precursor may be at least partiallysaturated. As used herein throughout the specification and the claims,“partially saturated” means hydrogenated to decrease the degree ofunsaturation of the macromonomer. In some examples, the degree ofunsaturation may be less than or equal to 50%, alternatively less thanor equal to 10%. The degree of unsaturation is equal to the ratio of theIodine value after hydrogenation to the original Iodine value of thepolymer prior to hydrogenation. Hydrogenation may be carried out by avariety of processes familiar to those of ordinary skill in the artincluding, but not limited to, hydrogenation in the presence ofcatalysts, such as Raney Nickel, noble metals, soluble transition metalcatalysts, and titanium catalysts, for example.

Following hydrogenation, the precursor may be finally converted to amacromonomer by reacting the end-group of the precursor to obtain an atleast partially saturated macromonomer having a (meth)acrylate endgroup. The (meth)acrylate end group may be obtained by a variety ofmethods. For example, direct acrylation may be achieved by reacting theterminal end of a precursor having a hydroxyl or amino end group with(meth)acrylic acid, (meth)acrylic ester, (meth)acrylic halide, or(meth)acrylic anhydride to form the (meth)acrylate-terminatedmacromonomer.

Alternatively, the precursors having a hydroxyl, carboxylic acid, amino,or epoxy end group may be reacted with an acrylated isocyanate compound,such that the isocyanate group reacts with the hydroxyl, carboxylicacid, epoxy, or amino end group of the precursor. For example, aprecursor having a hydroxyl or carboxylic end group may be reacteddirectly with 2-isocyanatoethyl (meth)acrylate. In yet another example,the precursor having a hydroxyl, carboxylic acid, or amino end group maybe esterified by reaction with the epoxy groups of glycidyl(meth)acrylate resulting in (meth)acrylate terminal ends. The acrylatedisocyanate compound may be obtained by reacting an isocyanate-groupcontaining compound having a functionality of at least 2 with a hydroxyl(meth)acrylate. The isocyanate-group containing compounds having afunctionality of at least 2 include, but are not limited to,4,4′-diphenylmethane diisocyanate (MDI), cyclohexanediisocyanate,p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, toluenediisocyanate (TDI), p-xylene diisocyanate, hexamethylene dilsocyanate,4,4′-dicyclohexylmethane diisocyanate,1,4-bis(isocyanomethyl)-cyclohexane, p-tetramethylxylene diisocyanate,m-tetramethylxylene diisocyanate, and isophorone dilsocyanate. Thehydroxyl (meth)acrylate may include any hydroxyalkyl (meth)acrylates,the alkyl group having 2 to 10 carbons, such as 2-hydroxyethyl acrylate.

In yet another example, the macromonomers may be obtained by reactingthe precursors having an epoxy end group with (meth)acrylic acid, ahydroxyl (meth)acrylate, or an amino-alkyl (meth)acrylate.

The macromonomers having a (meth)acrylated terminal end may becopolymerized with one or more radically polymerizable monomers to forma (co)polymer. This may be achieved by free-radical polymerization ofthe macromonomers with the one or more radically polymerizable monomers.

In one example, the radically polymerizable monomers may comprisealkyl(meth)acrylate monomers having a structure according to formula(I):

wherein R is hydrogen or methyl, and R¹ is a linear, branched or cyclicalkyl residue with 1 to 40 carbon atoms. In some examples, R¹ may be anoptionally substituted hydrocarbyl in the form of a linear, branched orcyclic alkyl residue having 1 to 5 carbon atoms. Examples of monomersaccording to formula (I) are, among others, (meth)acrylates whichderived from saturated alcohols such as methyl(meth)acrylate,ethyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate,n-butyl(meth)acrylate, and tert-butyl(meth)acrylate. Preferably, thepolymer comprises units being derived from methyl methacrylate.

The radically polymerizable monomers may also comprise a mixture ofmonomers comprising the alkyl(meth)acrylate monomers having a structureaccording to formula (I), as well as vinyl aromatics, such as styreneand a-methyl styrene, fumarates, maleates, vinyl esters, acrylonitriles,ethylene, 1,3-dienes, and combinations thereof.

The copolymer obtained from the polymerization of the macromonomerdescribed above and the one or more radically polymerizable monomers mayhave a weight average molecular weight of from 5,000 to 1,000,000 g/mol.

The copolymer may be obtained by any known method, such as free-radicalpolymerization. Novel polymerization techniques such as ATRP (AtomTransfer Radical Polymerization) and or RAFT (Reversible AdditionFragmentation Chain Transfer) may alternatively be used to obtain thecopolymers. Conventional radical initiators that may be used include azoinitiators including but not limited to 2,2′-azodiisobutyronitrile(AIBN), 2,2′-azobis(2-methylbutyronitrile) and 1,1-azobiscyclohexanecarbonitrile; peroxide compounds, e.g. methyl ethyl ketone peroxide,acetyl acetone peroxide, dilauryl peroxide, tert.-butyl per-2-ethylhexanoate, ketone peroxide, methyl isobutyl ketone peroxide,cyclohexanone peroxide, dibenzoyl peroxide, tert.-butyl perbenzoate,tert.-butyl peroxy isopropyl carbonate,2,5-bis(2-ethylhexanoyl-peroxy)-2,5-dimethyl hexane, tert.-butyl peroxy2-ethyl hexanoate, tert.-butyl peroxy-3,5,5-trimethyl hexanoate,dicumene peroxide, 1,1-bis(tert.-butyl peroxy)cyclohexane,1,1-bis(tert.-butyl peroxy) 3,3,5-trimethyl cyclohexane, cumenehydroperoxide and tert.-butyl hydroperoxide.

The polymerization may be conducted at any temperature and pressure, andthe polymerization may be carried out with or without solvents, such astoluene, benzene and xylene, cyclohexane, heptane, octane, nonane,decane, dodecane, and mixtures thereof. Other solvents include mineraloils and synthetic oils (e.g. ester oils such as diisononyl adipate),and also mixtures thereof.

In an alternate method, the poly(meth)acrylate (co)polymer may beobtained in a first step before grafting the macromonomer precursors tothe polymeric backbone of the (co)polymer in a second step. For example,a method of preparing a copolymer may comprise forming apoly(meth)acrylate by radically polymerizing one or more monomersaccording to formula (II):

wherein R² is hydrogen or methyl, and R³ is selected from the groupconsisting of a hydroxyl (i.e. to provide a carboxylic acid), a halogen,and —OR⁴, wherein R⁴ is an alcohol, an amino-alkyl, an isocyanato-alkyl,or an optionally substituted hydrocarbyl (such as a (meth)acrylate toform an anhydride). The one or more monomers may also comprise a mixtureof monomers comprising the alkyl(meth)acrylate monomers having astructure according to formula (I), as well as vinyl aromatics, such asstyrene and a-methyl styrene, fumarates, maleates, vinyl esters,acrylonitriles, ethylene, 1,3-dienes, and combinations thereof to form a(co)polymer. Depending on the functionality of the (co)polymers, one ofthe farnesene-based macromonomer precursors may be reacted with thepoly(meth)acrylate to form polyfarnesene side chains on the polymericbackbone of the poly(meth)acrylate. For example, if thepoly(meth)acrylate is the result of radically polymerizing (meth)acrylicacid, the acid groups along the polymeric backbone of thepoly(meth)acrylate may be reacted with a farnesene-based macromonomerhaving a hydroxyl, amino, isocyanato, or epoxy end group. In anotherexample, if the poly(meth)acrylate is the result of radicallypolymerizing hydroxyalkyl (meth)acrylate, the hydroxyl groups along thepolymeric backbone of the poly(meth)acrylate may be reacted with afarnesene-based macromonomer having a carboxylic acid, isocyanato orepoxy end group.

The copolymers described herein may be incorporated into variouscompositions. For example, the copolymers may be combined with a baseoil containing at least one of an ester oil and a hydrocarbon oil toform a lubricant composition. In other examples, the copolymers may beincorporated into hydraulic fluid compositions, cosmetic compositions,or adhesive compositions.

EXAMPLES

The advantageous properties of this invention can be observed byreference to the following examples, which illustrate but do not limitthe invention.

Polyfarnesene Monol Synthesis

A polyfarnesene monol was prepared by combining 100 g oftrans-β-farnesene and 200 g of methyl-tert-butyl ether (MTBE) in apressure reactor and purged with nitrogen three times. Subsequently, 1.3g of n-butyl lithium was added to the reactor at room temperature; thereaction was monitored and the temperature controlled to stay below 40°C. After polymerization was completed (approximately 15 minutes), astoichiometric excess of propylene oxide (2.0 g) was added to the livingpolymerization solution, followed by adding methanol (1.3 g) forneutralization. The polymer solution was then transferred to athree-neck flask equipped with a stirrer, and mixed well for 10 minuteswith purified water to wash the polymer solution. The stirring wasstopped and over time the organic phase separated from the aqueousphase, at which point the aqueous phase was discharged and the pHdetermined. The washing step was repeated until the aqueous phase becameneutral (pH=7). The separated organic phase was transferred to anotherthree-neck flask and the MTBE solvent was removed under nitrogen purgewith heating (150° C.). When the majority of solvent was removed, thepolymer was steam stripped until one-half of the steam based on polymervolume was eliminated, then the polymer was nitrogen purged at 150° C.to pull out residual water. The isolated polyfarnesene macromonomerprecursor having a hydroxyl end group was cooled to 70° C. andtransferred to a container. The molecular weight of the polyfarnesenemacromonomer precursor was approximately 5000 g/mol.

Hydrogenation

319 g of the polyfarnesene macromonomer precursor having a hydroxyl endgroup, 7.2 g of Ni catalyst and 336 g of heptane as a solvent weretransferred to a pressure reactor, followed by three nitrogen purges.The reaction temperature was set to 100-130° under nitrogen pressure.Before reaching the boiling point of the solvent, the reaction mixturewas purged with hydrogen another three times and hydrogen wascontinuously fed for the reaction. The reaction temperature wascontrolled by stirring speed and hydrogen pressure. In order to monitorthe reaction, aliquots of sample were taken and FTIR was performed afterdrying the solvent, measuring the disappearance of peaks associated withresidual unsaturation. This procedure was repeated until the peaksassociated with unsaturated disappeared completely. After the reaction,the reaction mixture was cooled down to room temperature and thecatalyst was removed by filtration. The final solution was stripped in aroto-evaporator under vacuum and the hydrogenated macromonomer precursorwas isolated. The iodine value and hydroxyl value were determined fromtitration.

Acrylation

Urethane acrylates were prepared by reacting isophorone diisocyanate(IPDI) with 2-hydroxyethyl acrylate (HEA) to make acrylated isocyanate,and followed by reacting with the hydrogenated macromonomer precursor.25 g of IPDI, 0.25 g of Irgonox 101 and 0.25 g of dibutyltin dilaurate(DBTDL) were transferred to a resin kettle equipped with a mechanicalstirrer, thermocouple, dropping funnel and air spurge. 11.9 g of2-hydroxyethyl acrylate (HEA) was continuously added to the reactionmixture at room temperature. The reaction temperature was 40° C. aftercompete addition. 0.17 g of Irgonox 1010 and 0.25 g of DBTDL was addedto the reactor, and 125 g of hydrogenated macromonomer precursor wasgradually added increasing the temperature to 70° C. An aliquot ofreaction mixture was taken out to measure NCO value after 1 hourreaction. Additional hydrogenated macromonomer precursor was added untilthe NCO value fell below 1.0 mg KOH/g.

The polyfarnesene monol synthesis and hydrogenation methods wererepeated to obtain samples of polyfarnesene of varying molecular weight.Comparative samples of polybutadiene monol and polyisoprene monol wereprepared according to the same method, except that the trans-β-farnesenewas replaced with either butadiene or isoprene. MolecularCharacterization. Standard size exclusion chromatography (SEC) wasutilized to determine molecular weight and molecular weightdistributions of the polymer samples on an Agilent 1260 Infinityinstrument in tetrahydrofuran (THF) using a guard column followed by twoAgilent ResiPore columns in series with refractive index detection.Number and weight average molecular weight (M_(n), M_(w)) andpolydispersity (M_(w)/M_(n)) values for low molecular weightpoly(butadienes) were determined using an in-house polybutadienecalibration curve. Low molecular weight polyisoprene and polyfarnesenevalues were determined using poly(styrene) calibration standards. Whileit is known that the choice of calibration standards can affect thereported molar mass, especially if structural differences between thecalibration polymer and measured polymer exist, this technique has beenchosen as it is a common practice.

¹H Nuclear Magnetic Resonance (¹H NMR) was used to determine themicrostructure of poly(trans-p-farnesene) using a Bruker Avance III 400MHz spectrometer with CDCl₃ as a solvent. Peak assignments forpoly(trans-β-farnesene) have been reported in the literature. FourierTransform Infrared Spectroscopy (FTIR) was performed on a Bruker Tensor37 with an attenuated total reflectance attachment.

Thermal Properties.

Thermal properties of the samples were determined using a TAInstruments, Inc. DSC Q2000 differential scanning calorimeter. Sampleswere prepared in aluminum hermetically sealed pans, equilibrated at 100°C. for one minute, cooled, and subjected to a temperature ramp at 10°C./minute from −150° C. to 100° C. Glass transition (T_(g)) at theinflection point was recorded.

Viscosity.

Viscosity was measured by Brookfield viscometers, model DV-II+Pro andDV-II+viscometer at various temperatures.

Various samples of non-hydrogenated polyfarnesene macromonomer precursorhaving a hydroxyl end group of similar Tg, vinyl %, molecular weight,and viscosity at 25 C were compared to samples of non-hydrogenatedpolybutadiene macromonomer precursor having a hydroxyl end group ofsimilar Tg and molecular weight. The results are provided in Table 1 andmolecular weight vs. viscosity plotted in FIG. 1.

TABLE 1 Precursor Monomer Farnesene Farnesene Farnesene ButadieneButadiene sample 1 sample 2 sample 3 sample A sample B Mn (g/mol) 21902920 5030 1700 5000 Tg (° C.) −57 −55 −62 −56 −57 1, 2/3, 4 40 40 40 6565 content (%) Visc @ 479 662 1355 4343 25997 25 C. (cp)

In FIG. 1, the polyfarnesene macromonomer precursors having a hydroxylend group exhibited a much lower viscosity than the butadiene-basedmacromonomer precursors having a hydroxyl end group of approximately thesame molecular weight.

The viscosity of hydrogenated polybutadiene (PolyBd) vs. polyfarnesene(PolyFENE) macromonomer precursors having a hydroxyl end group wasfurther investigated by comparing samples having different molecularweights. The results are provided in Table 2 with viscosity vs.temperature plotted on a logarithmic scale in FIG. 2.

TABLE 2 Sample HLBH5000M HFENE20kM HFENE5000M HFENE35kM HLBH1500M TypePolyBd PolyFENE PolyFENE PolyFENE PolyBd Mn 5000 20000 5000 35000 1500(g/mol) Temp (° C.) Viscosity (cp) 25 64,686 49,677 8,158 129,000 13,39735 25,745 22,395 3,499 57,175 5,179 45 11,857 11,018 1,710 28,244 2,23555 5,879 5,879 917 14,997 1,085 65 3,189 3,359 530 8,561 570 75 1,7271,910 4725 85 1,067 1,215 3020 95 690 815 2025

FIG. 2 demonstrates that the polyfarnesene macromonomer precursorshaving a hydroxyl end group may exhibit approximately the same viscosityas a polybutadiene macromonomer precursor having a hydroxyl end group,despite having three to four times the molecular weight of thepolybutadiene macromonomer precursor.

Additional samples of unfunctionalized polymers of farnesene, butadiene,and isoprene were prepared to determine the relationship between 1,2/3,4content and Tg. The results are provided in Table 3 and vinyl contentvs. Tg plotted in FIG. 3.

TABLE 3 1, 2/3, 4 Polydispersity Content Type Mn (g/mol) Index (%) Tg (°C.) Polybutadiene 1 4,300 1.1 28 −84 Polybutadiene 2 3,900 1.1 70 −40Polybutadiene 3 4,700 1.1 85 −28 Polybutadiene 4 5,200 1.1 90 −15Polyisoprene 1 3,190 1.35 9 −67 Polyisoprene 2 2,470 1.25 56 −32Polyisoprene 3 2,820 1.32 73 −8 Polyisoprene 4 3,110 1.59 85 0Polyfarnesene 1 10,370 1.23 9 −75 Polyfarnesene 2 10,650 1.19 39 −73Polyfarnesene 3 10,580 1.05 52 −70

In FIG. 3, the slope of the plots of 1,2/3,4 content vs. Tg for thepolyfarnesene macromonomer precursors having a hydroxyl end group isless that the slope of the similar plots for the polybutadiene andpolyisoprene macromonomer precursors having a hydroxyl end group. Thisindicates that 1,2/3,4 content has much less effect on the Tg for thepolyfarnesene macromonomer precursors.

It will be understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.Relational terms such as first and second and the like may be usedsolely to distinguish one entity or action from another withoutnecessarily requiring or implying any actual such relationship or orderbetween such entitles or actions. The terms “comprises,” “comprising,”“includes,” “including,” or any other variation thereof, are intended tocover a non-exclusive inclusion, such that a process, method, article,or apparatus that comprises a list of elements does not include onlythose elements but may include other elements not expressly listed orinherent to such process, method, article, or apparatus. An elementpreceded by “a” or “an” does not, without further constraints, precludethe existence of additional identical elements in the process, method,article, or apparatus that comprises the element. The terms “and” and“or” may have both conjunctive and disjunctive meanings.

Unless otherwise stated, any and all measurements, values, ratings,positions, magnitudes, sizes, and other specifications that are setforth in this specification, including in the claims that follow, areapproximate, not exact. They are intended to have a reasonable rangethat is consistent with the functions to which they relate and with whatis customary in the art to which they pertain.

While the foregoing has described what are considered to be the bestmode and/or other examples, it is understood that various modificationsmay be made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that they may be appliedin numerous applications, only some of which have been described herein.It is intended by the following claims to claim any and allmodifications and variations that fall within the true scope of thepresent concepts.

We claim:
 1. A macromonomer precursor comprising: a polymeric chainderived from farnesene; and a single functional terminal end selectedfrom a hydroxyl group, an amino group, an epoxy group, an isocyanatogroup, and a carboxylic acid group.
 2. The macromonomer precursor ofclaim 1, wherein the polymeric chain is less than or equal to 10%saturated.
 3. The macromonomer precursor of claim 1, wherein thefarnesene comprises at least 25 wt. % of the macromonomer precursor. 4.The macromonomer precursor of claim 1 having a weight average molecularweight of from 1,000 to 100,000.
 5. The macromonomer precursor of claim1, wherein the polymeric chain is derived from farnesene and monomerselected from dienes, vinyl aromatics, and combinations thereof.
 6. Acopolymer derived from monomers comprising: a) radically polymerizablemonomers; and b) one or more macromonomers comprising a polymeric chainderived from farnesene, and a (meth)acrylate functionalized terminalend.
 7. The copolymer of claim 6, wherein the radically polymerizablemonomers comprise alkyl(meth)acrylate monomers having a structureaccording to formula (I):

wherein R is hydrogen or methyl, and R¹ is a linear, branched or cyclicalkyl residue with 1 to 40 carbon atoms.
 8. The copolymer of claim 7,wherein the radically polymerizable monomers further comprise vinylaromatics, fumarates, maleates, vinyl esters, acrylonitriles, andcombinations thereof.
 9. The copolymer of claim 4, wherein the radicallypolymerizable monomers further comprise ethylene, 1,3-dienes, styrene,α-methyl styrene, and combinations thereof.
 10. The copolymer of claim 6having a weight average molecular weight of from 5,000 to 1,000,000. 11.The copolymer of claim 6, wherein the one or more macromonomerscomprises a single (meth)acrylate functionalized terminal end.
 12. Alubricant composition comprising base oil containing at least one of anester oil and a hydrocarbon oil; and the copolymer of claim
 3. 13. Ahydraulic fluid composition comprising the copolymer of claim
 3. 14. Acosmetic composition comprising the copolymer of claim
 3. 15. Anadhesive composition comprising the copolymer of claim
 3. 16. A methodof preparing a copolymer comprising: reacting a macromonomer precursoraccording to claim 1 with a reactant according to formula (II):

wherein R² is hydrogen or methyl, and R³ is selected from the groupconsisting of a hydroxyl, a halogen, a (meth)acrylate, and —OR⁴, whereinR⁴ is a substituted hydrocarbyl to provide a (meth)acrylate terminatedpolyfarnesene macromonomer; and copolymerizing the (meth)acrylateterminated polyfarnesene macromonomer with one or more radicallypolymerizable monomers.
 17. The method of claim 16, wherein themacromonomer precursor is at least partially saturated prior to thereacting step.
 18. The method of claim 16, wherein the optionallysubstituted hydrocarbyl is a linear, branched or cyclic alkyl residuehaving 1 to 5 carbon atoms.
 19. A method of preparing a copolymercomprising: reacting a macromonomer precursor according to claim 1having a hydroxyl group, an amino group, and a carboxylic acid groupwith glycidyl (meth)acrylate to provide a (meth)acrylate terminatedpolyfarnesene macromonomer; and copolymerizing the (meth)acrylateterminated polyfarnesene macromonomer with one or more radicallypolymerizable monomers.
 20. The method of claim 19, wherein themacromonomer precursor is at least partially saturated prior to thereacting step.
 21. A method of preparing a copolymer comprising:reacting a macromonomer precursor according to claim 1 having a hydroxylgroup, an amino group, an epoxy group, and a carboxylic acid group withan acrylated isocyanate compound to provide a (meth)acrylate terminatedpolyfarnesene macromonomer; and copolymerizing the (meth)acrylateterminated polyfarnesene macromonomer with one or more radicallypolymerizable monomers.
 22. The method of claim 21, wherein themacromonomer precursor is at least partially saturated prior to thereacting step.
 23. A method of preparing a copolymer comprising:radically polymerizing monomers according to formula (II) to form apoly(meth)acrylate):

wherein R² is hydrogen or methyl, and R³ is selected from the groupconsisting of a hydroxyl, a halogen, and —OR⁴, wherein R⁴ is an alcohol,an amino-alkyl, an isocyanato alkyl, or an optionally substitutedhydrocarbyl; and reacting the poly(meth)acrylate with the macromonomerprecursor of claim
 1. 24. The method of preparing a copolymer accordingto claim 23, wherein the monomers according to formula (II) areradically polymerized with monomers selected from vinyl aromatics,fumarates, maleates, vinyl esters, acrylonitriles, ethylene, andcombinations thereof.
 25. A copolymer made according to claim
 23. 26. Alubricant composition comprising base oil containing at least one of anester oil and a hydrocarbon oil; and the copolymer of claim
 25. 27. Ahydraulic fluid composition comprising the copolymer of claim
 25. 28. Acosmetic composition comprising the copolymer of claim
 25. 29. Anadhesive composition comprising the copolymer of claim 25.